Quem Sai Aos Seus Não Degenera

I came across this fairly baffling sentence in an exercise. What on earth can it mean? Googled it to see if I could find anyone using it and apparently, yes, it’s an expression, the gist of which is that, if you follow your parents’ guidance you won’t go far wrong in life. There’s an example here, referring to sporty kids following in the footsteps of their sporty parents.